The invention relates to a cushion for a seat.
Known seats, for example in motor vehicles, consist of a bearing structure and upholstered cushions, possibly with other components mounted between them. In order to improve ergonomics and comfort, e.g., in vehicle seats, usually adjusting possibilities are provided in order to change, for example, the inclination of the seat surface and/or the backrest, the width of the backrest, etc. Besides that, additional devices like a lumbar support or a massage apparatus may be provided.
The adjusting possibilities will ensure the best possible adaptation of the seat to the individual physiological form of the spinal column and the lower extremities of the person using the seat to ensure the best possible seat comfort. Maximum comfort is achieved if the seat surface and the backrest correlate as congruently and homogeneously as possible with the physiological shape of the person.
For this purpose, placement on a bearing structure of a cushion that has loose filling material or a fluid that can be redistributed with the use of magnetic or electrical fields by application of electrical current, by heating, or by hydraulic excitation, is known, e.g., from DE 10 2006 032 891 A1, in order in this way to adapt the shape of the seat surface and the backrest to the physiological form of the seat user. In addition, DE 695 05 131 T2 describes a cushion for a seat, which as a so-called “vacuum seat” is provided with a bulk material that flows, wherein the cushion can adapt to the body shape of the seat user in that a multi-layer system is moved toward the seat user by application of compressed air.
What is disadvantageous with the known systems is their considerable construction volume and weight.
The object of the invention is to provide a cushion for a seat, especially a seat for a motor vehicle, that is characterized by a simple structure and a low weight with low installation space requirements.
This and other objects are achieved by a cushion according to the invention, as well as a seat with the cushion and methods for adapting the contour of such a seat.
In one aspect of the invention, a known spacer structure with layers arranged parallel to each other that are connected to each other by spacer threads is brought into a casing that is fluid-tight. The casing has a hose line or a connection for a hose line in order to be able to influence the quantity of the liquid inside the casing.
Preferably, the layers arranged parallel to each other are designed as layers of knitted material. However, the spacer structure can naturally have any other type of suitable material instead of the knitted layers, for example fabric layers.
Spacer structures, as described above, are known, e.g., from DE 90 16 062 U1, EP 0 529 671 B1 and DE 10 2006 023 357 A1. Textile spacer structures such as these are distinguished by their elastic upholstery properties under a pressure loading on the surface of the knitted fabric. They are used in mattresses made up of multiple layers, in upholstery covers, etc.
Because of the integration according to the invention of the known spacer structures in a fluid-tight casing with a connection for a hose line, the possibility is produced of “freezing” the form of the spacer structure that results under the load of a seat user, in that after loading of the cushion, the hose line is blocked and/or a vacuum is applied to the inside of the casing. Thus, with cushions that have a relatively thin design, an exact contour adaptation to the body shape of a user can be achieved, which results automatically from the user sitting down and is then fixed. If a different seat user sits down on the seat, the fixing of the cushion is eliminated and a new contour adaptation to the body shape of the following seat user occurs.
On its outside, the cushion has a cover layer that corresponds to the cover layer of known cushions, that is consisting of a textile material, of leather, or the like. To increase the seat comfort, below the cushion a back padding of yielding material, e.g., a foam layer, can be provided to increase the seat comfort.
In a preferred application of the invention, the cushion is used on a non-upholstered bearing structure of a seat, especially on a bearing structure as is described in co-pending application Ser. No. 13/186,220, entitled “Process for Producing a Supporting Shell for a Seat,” filed on even date herewith, the disclosure of which is herein expressly incorporated by reference.
Because of the bearing structure, a body-contoured seat is provided that makes possible very good seat comfort. In an especially advantageous manner, the great seat comfort already results in the cushion according to the invention with only little thickness, i.e., little distance of the two knitted layers of the spacer structure, because the contouring of the bearing structure already achieves an adaptation to the body shape of the seat user in question.
The cushion covers, completely or at least almost completely, the entire area of the seat surface and/or the backrest of the bearing structure and thus forms the direct support surface for the seat user. To increase the seat comfort, preferably several cushions are provided, which together cover the area of the seat surface and the backrest.
In one embodiment of the invention, the seat surface area is divided into two, and preferably into three, cushions arranged one after the other. In an analogous manner, the backrest area is divided into three cushions, arranged one above the other. In principle, a higher or a lower number of cushions can also be selected.
The cushions can be divided over the width extension of the seat surface and/or the backrest so that a right/left division results, whereby an individual seat adjustment can occur for the two halves of the body. Naturally, a finer division can also be selected for optimizing the contour adaptation, while weighing the costs connected with the finer division.
In a simplified embodiment of the invention, only one single cushion can be provided per body half in the area of the seat surface and/or the backrest.
Fixing the contour created by a seat user of a cushion according to the invention can occur in that a blocking device is activated in the hose line of the cushion as soon as the seat user compresses the spacer structure and the air has been at least partially displaced from the fluid-tight casing. Because of the reduced air volume in the inside of the fluid-tight sleeve, during unloading, the spacer frame cannot return to its original shape as a result of the retracted casing so the contour of the spacer frame is fixed.
In another embodiment of the invention, a pumping device can be connected to one or more cushions, with which the fluid can be drawn out of the inside of the cushion(s) (suction pump).
Because of the lower pressure on the inside of the cushion(s), an improved contour adaptation of the cushion(s) is achieved when the seat user sits down. Also with lower pressure applied, the contour of the cushion(s) is maintained better after the person leaves the seat than in the casing without a pumping device. In addition, the firmness of the cushion(s) can be regulated by the magnitude of the low pressure when the seat is occupied. In this way, for example, a configuration of the seat firmness in the gradation “comfort”—“normal”—“sport” can be implemented. In principle, a lower pressure is connected with greater firmness of the cushion(s) since the low pressure draws the casing of the cushion(s) together more strongly, by which the elastic spacer frame is compressed.
On the other hand, by use of a pumping device, a fluid can be pumped into the inside of the cushion(s) (positive displacement pump). In this way, a faster and more complete return of the cushion(s) to its/their original uncontoured form is achieved when the seat is unoccupied than is achieved during a self-resetting of the cushion(s) after the end of the loading by the seat user. In addition, with a positive displacement pump operating as a pumping device, an excess pressure can be created in the cushion and/or in the cushions in order to partially firm the cushion surface and/or to create an adjusting motion in the direction of the seat user. Because of this body support function a lumbar support, for example, can be created. Also, with the use of a more complex control of one or more pumping devices in connection with a number of cushions, massage and mobilizing effects can be created.
The fluid is preferably air. However, the cushion and/or cushions can also be filled with a fluid other than air, e.g., with a mixture of water and ethylene glycol or with an oil-like liquid with low viscosity.
The fluid, especially a fluid medium, can be tempered such that with the use of the warmed and/or cooled fluid an increase in comfort for the seat user can be achieved, at least during the sitting phase.
In another embodiment of the invention, a pressure sensor can be provided in at least one hose line of a cushion in order, in connection with a control or regulating device, for the fluid pressure on the inside of the casing to be controlled and/or regulated. In this way, the contour adaptation of the cushion to the seat user can be further improved. In addition, the body support, massage and/or mobilizing functions already mentioned can be implemented in this way. For massaging devices, different functional patterns, e.g., a massage wave running in a longitudinal or height direction of the seat can be implemented with the use of a control or regulation unit. Preferably, the functional pattern is repeated periodically.
If a pumping device is provided, it preferably acts on all or at least a majority of the cushions. The cushions are connected to the pumping device by way of hose lines and possibly valves.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.